Visual tracking of viral infection dynamics reveals the synergistic interactions between cucumber mosaic virus and broad bean wilt virus 2

Abstract

Cucumber mosaic virus (CMV) is one of the most prevalent plant viruses in the world, and causes severe damage to various crops. CMV has been studied as a model RNA virus to better understand viral replication, gene functions, evolution, virion structure, and pathogenicity. However, CMV infection and movement dynamics remain unexplored due to the lack of a stable recombinant virus tagged with a reporter gene. In this study, we generated a CMV infectious cDNA construct tagged with a variant of the flavin-binding LOV photoreceptor (iLOV). The iLOV gene was stably maintained in the CMV genome after more than four weeks of three serial passages between plants. Using the iLOV-tagged recombinant CMV, we visualized CMV infection and movement dynamics in living plants in a time course manner. We also examined whether CMV infection dynamics is influenced by co-infection with broad bean wilt virus 2 (BBWV2). Our results revealed that no spatial interference occurred between CMV and BBWV2. Specifically, BBWV2 facilitated the cell-to-cell movement of CMV in the upper young leaves. In addition, the BBWV2 accumulation level increased after co-infection with CMV.

Differential regulation of miRNAs involved in the susceptible and resistance responses of wheat cultivars to wheat streak mosaic virus and Triticum mosaic virus

“…Table S 3 ). This interplay of differential expression induced by two distinct plant viruses could render the plant even more susceptible state, potentially leading to a more severe infection due to the synergistic effect [ 21 , 33 ].…”

The VP53 protein encoded by RNA2 of a fabavirus, broad bean wilt virus 2, is essential for viral systemic infection

“…The visualization of GFP fluorescence signals in living plants was performed using a FOBI fluorescence imaging system (NeoScience, Korea) equipped with a blue light source (excitation at 470 nm) and an emission filter (530 nm short-pass), which effectively eliminates auto-fluorescence signals from chlorophyll 22 . Cellular fluorescence signals in plant leaf tissues were observed using a Leica SP8 laser-scanning confocal microscope (Leica, Germany) equipped with specific laser/filter combinations for GFP (excitation at 488 nm, detection between 510 and 550 nm), aniline blue (excitation at 405 nm, detection between 460 and 500 nm), and chloroplasts (excitation at 568 nm, detection between 580 and 620 nm).…”

“…The sequence data were analyzed using ClustalW implemented in MEGA X software 50 . To quantify the accumulation levels of (+)-strand BBWV2 RNAs, RT followed by quantitative PCR (RT-qPCR) was performed using the 2X SYBR Green Real-Time PCR Smart mix (Solgent, Korea) and iCycler iQ5 detection system (Bio-Rad, USA) with the following specific primers: BBWV2-R1-Fw (5′-TCACAGGTTATGCCGCTTGT-3′) and BBWV2-R1-Rv (5′-TCACTCGTCCCAAGCTGTTC-3′) for BBWV2 (+)-strand RNA1 detection; BBWV2-R2-Fw (5′-CCAGAGAAGTGGTTGGTCCC-3′) and BBWV2-R2-Rv (5′-TCCAACAGGTAATGCCCACC-3′) for BBWV2 (+)-strand RNA2 detection 22 . Strand-specific RT-qPCR was performed to quantify the accumulation levels of (-)-strand BBWV2 RNAs.…”

“…However, it has not been demonstrated whether VP53, the N-terminally 128-amino-acid-extended form of VP37, is truly expressed during viral replication and required for successful infection of BBWV2. In our previous studies, we generated infectious cDNA clones of BBWV2 RNA1 and RNA2 using a T-DNA-based binary vector that can be delivered into plant cells via Agrobacterium-mediated inoculation (agroinfiltration) 6 , 22 , 23 . In the present study, utilizing this BBWV2 infectious cDNA clone system, we generated various recombinant and mutant constructs of BBWV2 RNA2 to examine whether VP53 is expressed from RNA2 and necessary for BBWV2 infection.…”

Molecular mapping of the broad bean wilt virus 2 resistance locus bwvr in Capsicum annuum using BSR-seq

“…The co-infection rate reached 55.1% in 2016 (Kwon et al 2018 ). A synergic interaction was observed between CMV and BBWV2 in co-infected Nicotiana benthamiana plants using a visual tracking method (Kwon et al 2023 ). This study demonstrated that BBWV2 facilitates the cell-to-cell movement of CMV in upper younger leaves and that the accumulation of BBWV2 increases in plants co-infected with CMV.…”